Wire straightening machine



Jan. 19, 1937. l. 1'. LEECH 2,067,972

WIRE STRAIGHTENING MACHINE Filed June 18, 1930 s sheets-sheet 1 FEMN f wx NN i "I Jan., 19,1937. r J. T. LEEcH 2,057,972

WIRE STRAIGHTENING MACHINE Filed June 18, 1930 3 Sheets-Sheet 2 MIM lI/QTVENTR if Jan. 19, J, 'T LEECH 'wlRE STRAIGHTENING MACHINE 3 Sheets-Shea?l 3 Filed J une 18, 1950 E A we: H A W w v @H In "Mmm INVENTOR Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE WIRE STRAIGHTENING MACHINE Jacob T. Leech, Beaver,.Pa. i

Application June 18, 1930, Serial No. 461,948

23 Claims.

This invention relates to the art of straightening wire and especially wire of relatively large diameter which is to be subsequently cut up into straight lengths to be sold as rods.

It is well recognized in the art that wire which is drawn through a die and wound up upon a reel,

.the tension of drawing being effected by the winding up of the wire on the reel, hasto be straightened before it can be cut up into straight lengths suitable, for instance, as stock for screw machines. This is due to the fact that as the wire winds upon the reel there is a diierence in diameter between the inner surface and the outer surface of the coil equal to the diameter of the rod or wire. This necessitates the relative stretching of one side of the wire and the relative compression of the other side.

The most successful mechanism for straightening wire heretofore provided comprised a revolving head adapted to be rotated at high speed. The wire is passed through this head, which is substantially in the shape of a cylinder, and within the head are a series of shoes which bear against the wire, one of these shoes having the wire engaging face thereof eccentric so as to bow the wire as it passes through the head. .The shoe, being carried by the head, rotates around the wire so that with a revolution of the head the wire has been bowed in every direction from the I normal center line.

This type of apparatus is most generally known as the Schuster type of straightener. The wire must be drawn longitudinally through the head so that it will be progressively bowed by the eccentric shoe. friction to resist the endwise movement of the wire. All of the shoes bear against the Wire as the head rotates, and this is a further source of friction. The speed at which the wire can be straightened depends upon the speed at which the head can be rotated. If the head is rotated too fast and the speed ofthe wire is increased, the heat of friction galls or mars the wire so that it cannot be used as first class stock. Therefore, of necessity, the wire can only be straightened at a moderately low rate of speed. It is estimated that there should be approximately three revolutions of the straightener for eachv inch of travel of the wire, and the present maximum speed is 1500 revolutions per minute. Consequently the wire cannot be straightened much faster than forty feet per minute.

According to the present invention there is provided a machine in which the straightening elements do not have to revolve about the wire.

These shoes exert a considerable` thus eliminating one source of friction and in which the wire engages rollers whose axes are transverse to the direction of travel vof the wire, so that there is practically no friction by reason of the longitudinal travel of the wire through the straightening mechanism.

The invention may be readily understood by reference to the accompanying drawings in which Figure 1 is a more or less diagrammatic view of a complete straightening unit embodying my invention;

Figure.2 is a longitudinal section through the straightening head itself Figure 3 is an end elevation of the straightening head; A

Figure 4 is a transverse section through the straightening head in substantially the plane of line IV-IV of Fig. 2;

Figure 5 is a transverse section through one of the guide roll units;

Figure 6 is a longitudinal section in substantially the plane of line VI-VI of Fig. 5; and l Figures 7, 8, 9, 'and 10 are fragmentary views showing a view of the many different roll arrangements which may be provided in the straightening head and in the guide roll units and showing how different arrangements of rolls can be used for wire of non-circular cross-section.

Referring to the drawings, 2 designates the bed of a machine of suitable construction. Carried on the bed is a straightening head or iiexing unit 3. At each end of the straightening head unit 3 are one ormore guide roll units 4. I have shown two of these guide roll units at each end of the straightening head unit. At the entrance end of the machine I have indicated pinch rolls 5 and at the finishing end of the machine I have shown similar rolls 6.

The straightening head unit shown comprises a rotatable head 1 having grooves 8 in the periphery thereof, these grooves being for the accommodation of driving belts, the driving belts and driving motor not being shown. On each end face of the rotatable member 1 is a trunnion lplate 9 having a hollow trunnion portion I0. These trunnion portionsk I0 are supported on ball-bearings H, the ball-bearings being carried in recesses in stationary supporting frames I2. By reason of this arrangement the head 1 can be rotated at high speedand comparatively little friction in the stationary stands I2.

Carried in the revolving head 'I is an adjustable frame I3, best shown in Fig. 4. This frame, re- Ceived Within a window I4 in the member 1, can

be positioned by the operation of adjusting screws I5, the ends of which are accessible on the periphery of the member 1, as clearly shown in Fig. 4.

Carried in the frame I3 is a cylindrical depressing unit I6. Ball-bearings I1 are preferably interposed between the periphery of the cylindrical member I6 vand the circular opening I8 in the frame I3. These ball-bearings I1 permit the unit I6 to remain stationary while the head 1 with its adjustable frame I3 revolves around it. In the depressing head or cylinder I6 are a plurality of longitudinally extending intersecting slots I9. In each slot I have shown a wire engaging roller 20 carried on a pin 2 I. The slots I9 intersect at a central opening 22 in the member I6, and the peripheries of the rollers 20 project into the central opening 22. In Figs. 1, 2, 3, and 4 I have shown four of these rollers 20. lThe peripheries of them are concave so that together they deiine a circular pass 23 conforming to the diameter of the wire to be straightened and through which the wire to be straightened is passed. In Figs. 1, 2, and 3 I have shown this pass 23 as being directly at the center of the unit. However, in actual operation this pass is shifted to an eccentric position with reference to the center of rotation of the head 1. This adjustment may be effected by movement of the frame I3 through the operation of the adjusting screws I5. This may be readily understood by reference to Fig. 4 wherein the line A--A represents the vertical center line of the member 1 and the line B-B represents a vertical center line through the pass 23 defined by the several rollers 20.

The guide roll units 4 arranged at each side of themain flexing or depressing unit 3 comprise a standard'25 having a hollow head 26 within which is a removable cylinder 21. The cylinder 21 carries a plurality of small guide rollers 28 arranged in groups and forming a central pass 29 conforming to the shape and size of the wire being straightened. The cylinders 21 are adjustably retained in place by means of clamping screws 30. By loosening the screws 3U it is possible to replace the units 21 when a wire of different size or dierent shape is to be passed through the machine.

Those guide units immediately adjacent the -unit 3 are preferably adjustable longitudinally of the bed 2 so that they may be moved closer to or further away from the unit 3 as conditions may require. The passes 29 formed by the several sets of guide rollers 28 are all in alinement, and the axis of this pass coincides with the axis of rotation of the head 1 in the unit 3. The pass 23 `formed by the rollers 20 is eccentric to the axis of the passes 29 through the several groups of rollers 28.

In the operation of the machine, the wire is fed through the rollers 5, through the passes 29 of the guide rollei u nits 4, then through the Apass 23 formed by the rolls 20 in the flexing` unit.

From there it passes through the other guide units 4 and the pinch rolls 6. Since the pass 23 is eccentric to the axis of the wire, the wire is bowed in passingfrom the guide unit 4 on one side of the unit 3 to the guide unit 4 on the other side of the unit- 3. This is shown in Fig. 1.

By moving the two units 4 immediately adja- Vcent the unit 3 closer to the unit 3, the'curvature of the wire ismade more abrupt and by spreading the units 4 further apart, the curvature is made more gradual. It is for this reason that the units 4 are preferably adjustable longitudinally of the bed 2.

A 20 of course engaging the wire.

After the wire has been started through the machine as described, the head 1 is rotated at high speed by means of belts (not shown) engaging in a complete circle with each revolution of the head l 1. For instance, viewing Fig. 4, when the head 1 has rotated 180 degrees from the position shown, the line corresponding to the line B-B passing through the center of the passv23 would coincide with the line C-C. With a rotation of degrees from the position shown in Fig. 4 the line B--B would coincide with the line A-A, but the center of the pass would'be rai'sedor lowered from the position shown an amount equal to the eccentricity of the pass with reference to the center of rotation of the head 1. Thus while the member I6 with its rollers 20 does not revolve with the head 1, it is, due to its eccentric mounting of the head, caused to wabble or gyrate. The pass 23, with one revolution of the head 1, describes a complete circle about the center of rotation of the head. I haveshown a single group of rollers 20 in the head I6, but under some conditions and with some sizes of wire, more than a. single group can be used to advantage.

'I'he center of rotation of the head corresponds with the normal axis of the wire passing through the machine. With each rotation of the head, therefore, itwill be seen that the wire is ilexed from a normal position in every direction to the same extent by this gyratory or wabbling movement of the member I6 with its rolls 20, the rolls It will be seen also that while the wire is flexed in this way there is no rotational movement of the member L I6 about the wire. This means that the periphwire with the result that there is little frictional resistance offered to the longitudinal movement of the wire. The flexing unit 3 therefore effectively flexes the wire in every direction from a normal position to the necessary extent, as de- .termined by the adjustment of the screws I5.

without there being any relative rubbing action on the surface of the wire at all, either due to the longitudinal movement of the wire or due to the flexing action of the unit, thus'constituting a considerable improvement over that type of machine wherein the wire is drawn along the pressure shoes which' rotate about the surface y of the wire and in contact therewith.

Since'there is practically no frictional resistlance produced by either the flexing action or the longitudinal movement of the wire, the head 1 can easily be rotated at more than twice the speed of the revolving head of the ordinary type of straightener, and the wire can be accordingly fed through the machine at a very much'higher rate. In the absence of any friction between the wire and the straightening unit there is no marring of the finish on the wire, even at the higher speeds. The heat-generated in the previous machines has imposed one limitation on thel rubbing action being eliminated, the present invention enables the material -to be straightened at a much higher rate of speed and with much more satisfactory results.

In order to positively hold the member I against rotation I have shown an arm 3| having an inner end entered in one of the slots I9 and` having its other end bent down over the outside of the frame and entered in a keeper 3|', the keeper being large enough to allow the arm to oscillate with the movement of the member |6. A spring 3|a causes the arm 3| to follow the movement of rthe member I6 at all times. The arm functions to hold the member 4lli against rotation about its own axis but allows it to move about eccentrically.

In Figs. 1 to 7, inclusive, I have shown four rollers in both the flexing head and the guide bling action to the round strip.

In Fig. 9 there are shown complementary rollers 33 and 34, the peripheries of which comple- `ment each other to produce a hexagonal pass for In Fig. 10

accommodating a hexagonal stock. I have shown another modification of complementary rollers 35 in which three rollers instead of four are used to produce a hexagonal pass for the accommodation of hexagonal'stocks.

It will be obvious to those skilled in the art that other combinations. and arrangements of rolls may be used for different cross-sectional shapes of wire being straightened.

While I have specifically described one embodiment of my invention it will be understood that various changes and modifications may be made therein,A the same being for the purpose of illustration.

I claim:

1. In a wire straightening machine, a wire flexing unit comprising an inner member having a wire receiving pass therethrough of a shape and diameter conforming substantially to the shape and diameter of the wire to be straightened, an outer member' rotatable about the inner one' and in which the inner one is eccentrically positioned, a fixed support for the outer member at each end thereof, rotation of the outer member imparting a wabbllng motion to the inner one, and means on the xed support engaging the inner member for holding it against rotation with the outer member.

2. Inv a wire straightening machine, spaced apart wire guiding units having alined wire receiving and guiding passes therein, a flexing unit interposed between the spaced apart -wire guiding units comprising a member having comple- .mentary rollers therein whose axes are transwire receiving pass of the shape and size of the wire'to be straightened and which is eccentric to the alined passes in the guides, said rollers affording arolling contact' for the longitudinal movement 'of the wire through said member, and means for moving said member transversely in all directions about the longitudinal axis of the wire as it passes through the guides, said member having a passageway therethrough many times larger than the diameter ofthe wire and in which the rollers are located whereby the -wire contacts only with said guides and the rollers of the flexing unit. v

3. In a wire ,straightening machine, spaced apart wire guiding units having alined wire receiving and guiding passes therein, a flexing unit interposed between the spaced apart wire guiding units comprising a member having complementary rollers therein whose axes are trans- Verse to the axis of the wire passing through the guides and the peripheries of which contact at each side with the peripheries of adjacent rollers to define a Wire receiving pass which is eccentric to the alined passes in the guides, said rollers affording a rolling contact -for the longitudinal movement of the wire through said member, means for moving said member transversely about the longitudinal axis of the wire as it passes through the guides, and means for holding said member against rotation while adapting itself to the transverse movement of said member.

4. In a" wire straightening machine, a rotatable head having hollow trunnions thereon and having a driving surface on its periphery, a frame in which the trunnions are rotatably carried. an

eccentrically adjustable frame carriedv in `the head, said second frame having an opening therethrough providing an internal bearing surface, a cylindrical member in -said opening about which the second frame may revolve with the head, said member having a wire receiving pass therethrough conforming to the shape and diameter of the wire being straightened, said pass normally being eccentric to the axis of rotation of said head due to the eccentricity of the frame, and means beyond the ends of the trunnions constituting the only wire guiding and supporting elements for holding the wire at each sideof the said cylindrical member.

5. In a wire straightening machine, a rotatable head having hollow trunnions thereon, a frame in which the trunnions are rotatably carried, an eccentrically adjustable frame carried in the head, said second frame having an opening therethrough providing an internal bearing surface, a cylindrical member in said opening about which the second frame may revolve with the'head, said member having a wire receiving pass therethrough conforming to the shape and diameter ofthe wire being straightened, said pass normally being eccentric to the axis of rotation of said head due to the eccentricity of the frame, means vfor adjustably changing the eccentrcity of said second frame, and adjustable wire guides beyond the ends of the trunnions constituting the support for the wire at each side of the cylindrical member, the internal diameter of the trunnions being sufficient to provide for the angular displacement vof the wire between the cylindrical member and said guides.

6. In a wire straightening machine, a supporting frame structure, a rotatable head carried in said structure, a transversely adjustable frame carried in said head, said second frame having an openingtherethrough providing an internal bearing surface, a cylindrical member in said opening about which the second frame and head may rotate, said member having a central opening therethrough and having a plurality of rollers therein, the peripheries of which project into the central opening into contact with one another and form a closed wire receiving pass, the axes of the rollers being in a plane at vright angles to the axis of rotation of said head, the Wire receiving pass formed by said rollers being eccentric to the axis of rotation of the head, and means on the supporting frame structure engaging said cylindrical member to hold it against rotation with the rotatable head.

7. In a Wire straightening machine, a stationary frame structure, a flexing head ro-tatably supported on said structure, said head having a longitudinal opening therethrough, a transversely adjustable frame in said head having a longitudinally extending opening therethrough, a cylindrical member in the opening in said frame, a bearing being provided lbetween the outside of the cylindrical member and thevinterior of said frame, means for adjusting `said frame transversely of the head, a plurality of rollers carried in said cylindrical member, the peripheries of which cooperate to dene a wire receiving pass, the axes of the rollers being in a plane transverse to the axis of rotation of the head, and a wire guiding unit at each side of the flexing unit having rollers therein arranged similarly to the rollers in said cylindrical member and dening` longitudinal opening therethrough, a transversely adjustable frame in said head having a longitudinally extending opening therethrough, a cylindrical member in the opening in said frame, `a bearing being provided between the outside of the cylindrical member and the interior of said frame, means for adjusting said frame transversely of the head, a plurality of rollers carried in said cylindrical member, the peripheries of which cooperate to define a wire receiving pass, the axes of the rollers being in a plane transverse to the axis of rotation of the head, a wire guiding unit at each side of the flexing unit having rollers therein arranged similarly to the rollers in said cylindrical member and defining' a wire receiving pass, the longitudinal axis of the wire receiving pass in the guide units coinciding with the axis of rotation of said head, and means forl adjusting the guiding units toward and away from the flexing unit.

9. In a wire straightening machine, a stationary frame structure, a flexing head rotatably supported in said Aframe structure, said head having hollow trunnions on the side faces thereof projecting into the' frame. structure, bearings in the frame structure engaging said trunnions, an eccentrically positioned ilexing unit supported in said A,head and about which the head'may revolve, cooperating means on the frame and ilexing member or holding the latter against rotation with the head, and a wire guide at each side of the frame structure beyond the ends of said trunnions for supporting the wire in a position which is axial to the center of rotation of the head, said wire guides providing the only support for the wire as it passes from the-guides throughthe exing unit, the hollow trunnions being of suilicient internal diameter to provide for the angular displacement of the wire, said guides being adjustable toward and away from the ends of the trunnions.

10. In a wire straightening machine, a exing u nit comprising a rotatably supported outer member, an inner member -eccentrically positioned within the outer one and having a wire receiving pass therethrough of a shape anddiameter conforming to the size of the wire being straightened, said outer member being rotatable about the inner one, a supporting structure in which the outer member is mounted, means arranged for relative oscillating movement connecting the inner member and the supporting structure for holding the inner member against rotation, guiding units at each 'side of the exing unit having relatively fixed wire receiving passes therethrough whereby the wire is flexed without rotating the wire, and driving means on the periphery of said outer member.

11. A wire straightening device comprising a rotary head supported on hollow trunnions for rotation, a frame having bearings for the trunnions of, said rotary head on which said rotary head is supported, a normally stationary guiding unit at each end of the rotary head, a exing member having a pass therethrough eccentrically positioned in the rotary head and about which the head revolves, the head thereby serving to transmit a gyratory transverse movement to the iiexing member, the pass in the flexing member being out 'of alinement with the guiding units, and means connecting thel flexing member and frame and having an oscillating and a reciprocating connection with one of them for holding the flexing member against rotation while allowing for the gyratory transverse movement thereof.

12. In a wire straightening machine, spaced apart wire guiding means through which the Wire /is pulled, a iiexing unit between the spaced apart wire guiding means comprising a member having a pass therethrough conforming substantially to the diameter and shape of the wire, which pass Vis positioned eccentrically to the axis of the wire as it passes through the guides, means for moving said vmember through a circular path about the axis of the wire, a supporting frame, and means on the supporting frame for holding said member against free rotation while permitting movement thereof in a circular path, said last named means being independent of said means for moving the memberthrough a circular path.

13. In a wire straightening machine, a wire flexing unit comprising an inner member having a wire receiving pass therethrough, an outer member'rotatable about the inner one and in which the inner one is eccentrically positioned, a xed support for the outer member at each end thereof, rotation of the outer member imparting a wabbling motion to the inner one, and means on the `fixed support engaging the inner member for holding it against rotation with the oute member.

14. In awire straightening machine, a rotatable head having hollow trunnions thereon and having a driving surface on its periphery, a frame in which the trunnions are rotatably carried, an eccentrically adjustable frame carried inthe head, said second frame having an opening 4therethrough providing an 'internal bearingsurface, a cylindrical member in said opening about which the second frame may revolve with the head, said member having a wire receiving pass therethrough, said pass normally being eccentric J to the axis of rotationof said head, due to the eccentricity of the frame, and means beyond the ends of the trunnions constituting the only wire guiding and supporting elements for holding the wire at each side of the cylindrical member.

15. In a wire straightening machine, a rotatable head having hollow trunnions thereon, a frame in which the trunnions are rotatably carried, an eccentrically adjustable frame carried in thehead, said second frame having an opening therethrough providing an internal bearing surface, a cylindrical member in said opening about which the second frame may revolve with the head, said member having a wire receiving pass therethrough, said pass normally being eccentric to the axis of rotatoin of said head, due to the eccentricity of the frame, means for adjustably changing the eccentricity of said second frame, and adjustable Wire guides beyond the ends of the trunnions constituting the support for the wire at each side of the cylindrical member, the internal diameter of the trunnions being sufficient to provide for the angular displacement of the wire between the cylindrical member and said guides.

16. In a wire straightening machine, spaced wire is pulled, a flexing unit between the spaced apart wire guiding means comprising a member having a wire receiving pass therethrough, winch pass is positioned eccentrically to the axis of the wire so it passes through the guides, means for moving said member through a circular path about the axis of the wire, a supporting frame, and 'means on the supporting frame for holding said member against free rotation, while permitting movement thereof in a circular path, said last named means being independent of said means for moving the member through a circular path.

17. Apparatus for straightening rod-like metal stock, which includes stock-exing devices extending around the stock in rolling contact therewith and confining the stock from independent nals with said supporting means preventing ro-v tation of the arbor thereby. f

18. In a straightening machine, apparatus for finish-straightening long rod-like stock moving longitudinally, which includes two circular arrangements of rollers, as fulcrum roller sets, respectively located around the path of longitudinal movement of the long stock, and spaced from one another by a comparatively short distance, the center of said circular arrangements being in alinement with the center of the longitudinal y stock-path,.a third circular arrangement of rollers as a stock-iiexing system, located intermediate said fulcrum roller-sets but supported in position establishing the center of the iiexingroller system slightly eccentric to the centers of the circular fulcrum-roller sets; all said individual rollers having trunnions supported transversely of the stock-path and adapted for rolling engagement with the longitudinally moving long stock; stationary supporting means for the fulcrum-roller sets; supporting means for the rod-flexing roller-system; and means'imparting an exclusively revolutionary movement in small circles to the portion of said supporting means which carries said flexing-roller system, whereby the relatively short portions of the moving long stock progressively movingr between the two ful- Crum-roller sets is flexed in small circles about the center of its path of longitudinal movement.

19. In a straightening machine, apparatus for finish-straightening long rod-like stock moving longitudinally, which includes two circularly arranged sets of rollers, as fulcrum-rollers; stationary supporting means in which said sets respectively are located around the path of longitudinal movement of the long stock, and spaced from one another by a comparatively short distance, and with the centers of the sets in line with the ccnter of longitudinal movement of the long stock; a system of stock-flexing rollers, supporting means for said roller-system in which the rollers are mounted in a circle intermediate said fulcrum-roller sets; and means revolving thev portion of said supporting means in which said flexing system is mounted, in small circles, about the center of longitudinal movement of the long stock while the supporting means is held from rotation whereby the flexing roller system itself is given a movement exclusively of revolution and the short portion of the long stock between the two sets of fulcrum-rollers is flexed in small circles about i'ts center of longitudinal movement. v

20. In a straightening machine, apparatus for finish-straightening long rod-like stock fed thereto, continuously in one direction, which includes two sets of fulcrum rollers arranged comparatively close together along the path of longitudinal stock-movement, the rollers of each set extending around said path and having trun- /nions arranged transversely of said path; stationary supporting means for said fulcrum roller sets whereby they hold the moving stock in its path while the individual rollers are rotated by lthe moving stock; a system of stock-flexing rollers arranged in a circle between said sets of fulcrum-rollers; supporting means for said flexing-roller system and 'in which trunnions ofthe rollers are mounted transversely of the path of the stock; mechanism revolving the portion of said supporting means in which said fiexing-rollers are mounted, in relatively very small circles about the center of the path of longitudinal stock-movement while said supporting means ls held from rotation and while the individual flexing rollers are being rotated by the stock moving between them, thereby revolving the stock vin passage from one of the two sets of fulcrumrolls to the other, in very small circles about the center of its path of longitudinal movement.

21. In a straightening machine, apparatus for straightening long rod-like stock moving longitudinally, which includes two circular arrangements of rollers, as fulcrum roller sets, respectively located around the path of longitudinal movement of the long stock and spaced from one another by a comparatively short distance, the centers of said circular arrangements being in alignment with the center of the longitudinal stock path, a third circular arrangement of rollers as a stock-flexing systemflocated intermediate said fulcrum roller sets but supported in positions establishing the center of the flexing roller` sys'- tem slightly eccentric to the centers of the circucles to the portion of said supporting means which carries said flexing roller system, wherebyv the relatively short portions of the moving long stock progressively moving between the two fulcrum roller sets is iiexed in small circles about the center' of its path of longitudinal movement.

22. In a straightening machine, apparatus for straightening long rod-like stock fed thereto con-- tinuously in one direction, which includes two sets of iulcrum` rollers arranged comparatively close together along a path of longitudinal stock movement, the rollers of each set extending around said path and being supported for rotation on axes transverse to said path, stationary supporting means for said fulcrum roller sets whereby they hold the moving stock in its path while the individual rollers are rotated by the moving stock, a system of stock flexing rollers arranged in a circle between the sets of fulcrum rollers, supporting mea-ns for said iiexing roller system wherein the rollers are mounted for rotation on axes transverse to the path of the stock; mechanism revolving the portion of said supporting means in which said flexing rollers are mounted in relativelyvery small circles about the center of the path of longitudinal stock movement while said supporting means is held from rotation and while the individual flexing rollers are being rotated by the st ock moving between them, thereby revolving the stock in passage from one of the two sets of fulcrum rollers to the other in very-small circles about the center of its path of longitudinal movement.

23. A wire straightening device comprising a rotary head supported on hollow trunnions for rotation, a frameghaving bearings for the trunnions of said rotary head on which said rotary head is supported, a normally stationary guiding unit at each end ofthe rotary head, a exing member having a pass therethrough eccentrically positioned in the rotary head and about which the head revolves, the head thereby serving to transmit a gyratory transverse movement to the flexing member, the pass in the flexing member being out of 'alinement with the guiding units, a stationaryguide member on the frame, and a holding means engaging the exing member and the guide and movable up and down with respect to the guide and back and forth with respect thereto for anchoring the flexing member against rotation while permitting it to be carried around eccentrically.

JACOB 'I'. LEECH. 

